Bill Gates has warned the world that a deadly pandemic capable of killing tens of thousands could be started by a terrorist armed with a computer and knowledge of genetic engineering.

The Microsoft co-founder said being prepared for a global pandemic was as vital as nuclear deterrence and said the threat of a deadly, highly contagious disease came not just from terrorism, but also from nature.

Speaking at a Munich security conference, the richest man in the world warned: “We ignore the link between health security and international security at our peril.”

Mr. Gates who has spent billions of dollars supporting health initiatives worldwide, said: “The next epidemic could originate on the computer screen of a terrorist intent on using genetic engineering to create a synthetic version of the smallpox virus – or a super contagious and deadly strain of the flu.

“Whether it occurs by a quirk of nature or at the hand of a terrorist, epidemiologists say a fast-moving airborne pathogen could kill more than 30 million people in less than a year. And they say there is a reasonable probability the world will experience such an outbreak in the next 10 to 15 years.”

He added: “It’s hard to get your mind around a catastrophe of that scale, but it happened not that long ago. In 1918, a particularly virulent and deadly strain of flu killed between 50 million and 100 million people.”